Small-Disturbance Voltage Stability Study on Shaanxi Power System

Shaanxi power system consists of interconnected power networks serving Guanzhong region. In summer, when hydroelectricity is abundant, the thermal plants in Guanzhong provide relatively less power capacity and as the result, large blocks of power coming from Gansu network or Ankang power plants may potentially cause voltage collapse at the Guanzhong power system. In addition, even though Shaanbei, Ankang and Hanzhong network have longer distances from Guanzhong main network, they are prone to the possibility of voltage collapse whenever great power from main network enters their regions. In virtue of small-disturbance voltage stability program ofWPSASP, this paper studies thoroughly the voltage stability on Shaanxi grid using continuous power flow, sensitivity analysis and modal analysis methods. The results indicate subsistent problems and bottle-necks existed in Shaanxi power system at such, the results can provide important information for Shaanxi power system to operate more safely and stably.